2.1. COMMERCIAL PESTICIDES: GENERAL CONSIDERATIONS
Each year, significant portions of the world's commercially important agricultural crops are lost to insects and other pest infestation. The damage wrought by these pests extends to all areas of commercially important plants including foods, textiles, and various domestic plants, and the economic damage runs well into the millions of dollars. Thus, protection of crops from such infestations is of paramount concern.
Broad spectrum pesticides are most commonly used for crop protection, but indiscriminate use of these agents can lead to disruption of the plant's natural defensive agents. Furthermore, because of their broad spectrum of activity, the chemical pesticides may destroy non-target organisms such as beneficial insects and parasites of destructive pests. These are also frequently toxic to animals and humans, and thus, pose environmental hazards when applied.
Additionally, insects and other organisms have frequently developed resistance to these pesticides when repeatedly exposed to them. In addition to reducing the utility of the pesticide, resistant strains of minor pests may become major infestation problems due to the reduction of beneficial parasitic organisms.
This is a major problem encountered in using broad spectrum pesticides. What is needed is a biodegradable pesticide that combines a narrower spectrum of activity with an ability of maintaining its activity over an extended period of time, i.e., to which resistance develops much more slowly, or not at all. Biopesticides appear to be useful in this regard.